As discussed in the March 2001 STAN, various errors may exist in
TIME-TAG datasets. New archive software installed on 2001-Sep-13
repairs all known problems in TIME-TAG datasets. Every dataset
retrieved after 2001-Sep-13 should be free of TIME-TAG errors.

STIS MAMA detector electronics occasionally report an
erroneous time. The previous ground processing software
failed to properly trap these errors. As a result, gaps or
jumps in time could occur in processed TIME-TAG data.
Also, the existing ground software did not properly flux
calibrate data from observations in which the actual
exposure time differed from the EXPTIME keyword value
(i.e. the requested exposure time). This can happen when
STIS memory fills before it can be dumped, for example.
None of these issues affected STIS MAMA data obtained in
ACCUM mode. All investigators working with STIS TIME-TAG
data should read the more detailed discussion of possible
problems, and if they believe that
their data may have been affected, retrieve it again from
the archive.